It's the Old Army Game
In It's The Old Army Game, W.C. Fields is Elmer Prettywillie, proprietor of the local drug store, and Louise Brooks is his shop assistant.

“The silent W.C. Fields was slightly less endearing than the sound, partly due to the fact that Fields, shrewd vaudevillian that he was, was still engaged in building up his screen character. Over the years he whittled away at elements that didn't work, expanded on those that did. But in terms of sheer comedy, despite the lack of his voice and those glorious thrown-away asides, It's The Old Army Game still works well as a comedy, and there's an added bonus in seeing for the first time some of the key routines - such as the sleeping porch episode in this film - that he was to revise, polish, and re-present in his sound films. The silent Fields films were all made on the East Coast, and lacked the polish of the Hollywood comedies, but of course we now know that it was the rough edges that gave all Fields films, silent and sound, much of their bite.”